Thallium Centers Research Articles

Terpyridine isomerism as a tool for tuning red-to-NIR emissive properties in heteronuclear gold(I)-thallium(I) complexes.

The polymeric linear chain [AuTl(C6Cl5)2]n reacts with three terpyridine-type ligands substituted with thiophene groups containing N-donor centres in different relative positions (L1, L2 and L3), leading to the Au(I)/Tl(I) complexes [AuTl(C6Cl5)2(L1)]n (1), [{AuTl(C6Cl5)2}2(L2)]n (2) and [AuTl(C6Cl5)2(L3)]n (3). X-Ray diffraction studies reveal that L1 acts as a chelate, while L2 and L3 act as bridging ligands, resulting in different coordination indexes for the thallium(I) centre. These structural differences strongly influence their optical properties, and while compounds 2 and 3 emit near the limit of the visible range, complex 1 emits in the infrared region. DFT calculations have also been carried out in order to determine the origin of the electronic transitions responsible for their optical properties.

Synthesis and crystal structure of a triple-decker CuII3TlI2 complex: first example of a thallium(I) system in the imino-phenolate Schiff base ligand family

This report deals with the synthesis, characterization, and crystal structure of a heteropentanuclear CuII3TlI2 compound [(CuIIL)3TlI2](NO3)2 (1), where H2L=N,N′-ethylenebis(3-ethoxysalicylaldimine). This compound crystallizes in the monoclinic crystal system within space group C2/c. Each of the two symmetry related thallium(I) centers is located between a terminal and a common, central [CuIIL] by forming bonds with four phenoxo and three ethoxy oxygens. The three [CuIIL] moieties are parallel and hence 1 is a triple-decker system. Neighboring triple-decker moieties are interlinked by π⋯π stacking interaction and weak hydrogen bonds to generate 3-D self-assembly in 1. Salient features in the composition and structure of the title compound are discussed; the title compound is the first example of a thallium(I) system in imino-phenolate Schiff base family.

Benzannulated tris(2-mercapto-1-imidazolyl)hydroborato ligands: tetradentate κ4-S3H binding and access to monomeric monovalent thallium in an [S3] coordination environment.

The benzannulated tris(mercaptoimidazolyl)borohydride sodium complex, [Tm(Bu(t)Benz)]Na, has been synthesized via the reaction of NaBH4 with 1-tert-butyl-1,3-dihydro-2H-benzimidazole-2-thione, while [Tm(MeBenz)]K has been synthesized via the reaction of KBH4 with 1-methyl-1,3-dihydro-2H-benzimidazole-2-thione. The molecular structures of the solvated adducts, {[Tm(Bu(t)Benz)]Na(THF)}2(μ-THF)2 and [Tm(MeBenz)]K(OCMe2)3, have been determined by X-ray diffraction, which demonstrates that the [Tm(R)] ligands in these complexes adopt different coordination modes to that in {[Tm(MeBenz)]Na}2(μ-THF)3. Specifically, while the [Tm(MeBenz)] ligand of the sodium complex {[Tm(MeBenz)]Na}2(μ-THF)3 adopts a κ(3)-S3 coordination mode, the potassium complex [Tm(MeBenz)]K(OCMe2)3 adopts a most uncommon inverted κ(4)-S3H coordination mode in which the potassium binds to all three sulfur donors and the hydrogen of the B-H group in a linear KH-B manner. Furthermore, the [Tm(Bu(t)Benz)] ligand of {[Tm(Bu(t)Benz)]Na(THF)}2(μ-THF)2 adopts a κ(3)-S2H coordination mode, thereby demonstrating the flexibility of this ligand system. The monovalent thallium compounds, [Tm(MeBenz)]Tl and [Tm(Bu(t)Benz)]Tl, have been obtained via the corresponding reactions of [Tm(MeBenz)]Na and [Tm(Bu(t)Benz)]Na with TlOAc. X-ray diffraction demonstrates that the three sulfur donors of the [Tm(RBenz)] ligands of both [Tm(MeBenz)]Tl and [Tm(Bu(t)Benz)]Tl chelate to thallium. This coordination mode is in marked contrast to that in other [Tm(R)]Tl compounds, which exist as dinuclear molecules wherein two of the sulfur donors coordinate to different thallium centers. As such, this observation provides further evidence that benzannulation promotes κ(3)-S3 coordination in this system.

Thallium(I) complexes of fluorinated bis- and tris(pyrazolyl)borate ligands: [H2B{3,5-(CF3)2pz}2]Tl and [HB{3,5-(CF3)2pz}3]Tl

X-ray crystal structural data at 100 (2) K for the thallium(I) complex of a fluorinated bis(pyrazolyl)borate, {bis[3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl-κN(2)]borato}thallium(I), [Tl(C10H4BF12N4)], abbreviated as [H2B{3,5-(CF3)2pz}2]Tl, and the related tris(pyrazolyl)borate, {tris[3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl-κN(2)]borato}thallium(I), [Tl(C15H4BF18N6)], abbreviated as [HB{3,5-(CF3)2pz}3]Tl, are reported. [H2B{3,5-(CF3)2pz}2]Tl features a two-coordinate Tl(I) atom with a bent geometry and a boat-shaped bis(pyrazolyl)borate ligand. It also has several additional inter- and intramolecular Tl···H and Tl···F contacts in the solid state. The tris(pyrazolyl)borate analogue [HB{3,5-(CF3)2pz}3]Tl has a trigonal-pyramidal thallium centre and features inter- and intramolecular Tl···F contacts.

Thallium(i) complexes of dichalcogenido imidodiphosphinates {Tl[(EPiPr2)2N]}n (E = Te, Se, S): Synthesis, NMR spectra and a structural comparison

The homoleptic thallium(i) complexes {Tl[(EP(i)Pr(2))(2)N]}(n) (, E = Te; , E = Se; , E = S) have been obtained in 70-86% yields from the reaction of TlOEt with (TMEDA)Na[(EP(i)Pr(2))(2)N] in CH(2)Cl(2) or Et(2)O. Complexes were structurally characterised in the solid state by single crystal X-ray diffraction and in solution by multinuclear NMR spectroscopy ((31)P, (77)Se, and (125)Te). The solid-state structures of , and are comprised of one-dimensional coordination polymers. In and there are two distinct environments for both the thallium centres and the [(EP(i)Pr(2))(2)N](-) ligands. The denticities of the selenium centres in the ligands of differ significantly from those of tellurium donor atoms in giving rise to different coordination geometries at the chalcogen atoms in these two complexes; however, both possess edge-sharing Tl(2)E(4) octahedra as structural units. By contrast, the sulfur analogue exhibits only one ligand environment with trigonal pyramidal geometries for both sulfur centres and a distorted tetrahedral geometry for thallium generating vertex-sharing four-membered Tl(2)S(2) rings.

Thallium(III) complexes of the metalloligands [Pt 2(μ-S) 2(PPh 3) 4] and [Pt 2(μ-Se) 2(PPh 3) 4

Reactions of [Pt 2(μ-S) 2(PPh 3) 4] with the diarylthallium(III) bromides Ar 2TlBr [Ar = Ph and p-ClC 6H 4] in methanol gave good yields of the thallium(III) adducts [Pt 2(μ-S) 2(PPh 3) 4TlAr 2] +, isolated as their BPh 4 - salts. The corresponding selenide complex [Pt 2(μ-Se) 2(PPh 3) 4TlPh 2]BPh 4 was similarly synthesised from [Pt 2(μ-Se) 2(PPh 3) 4], Ph 2TlBr and NaBPh 4. The reaction of [Pt 2(μ-S) 2(PPh 3) 4] with PhTlBr 2 gave [Pt 2(μ-S) 2(PPh 3) 4TlBrPh] +, while reaction with TlBr 3 gave the dibromothallium(III) adduct [Pt 2(μ-S) 2(PPh 3) 4TlBr 2] +[TlBr 4] −. The latter complex is a rare example of a thallium(III) dihalide complex stabilised solely by sulfur donor ligands. X-ray crystal structure determinations on the complexes [Pt 2(μ-S) 2(PPh 3) 4TlPh 2]BPh 4, [Pt 2(μ-S) 2(PPh 3) 4TlBrPh]BPh 4 and [Pt 2(μ-S) 2(PPh 3) 4TlBr 2][TlBr 4] reveal a greater interaction between the thallium(III) centre and the two sulfide ligands on stepwise replacement of Ph by Br, as indicated by shorter Tl–S and Pt⋯Tl distances, and an increasing S–Tl–S bond angle. Investigations of the ESI MS fragmentation behaviour of the thallium(III) complexes are reported.

Photostimulated luminescence studies of γ-irradiated KBr 1−xI x:TlI mixed crystals

Results on photoluminescence and photostimulated luminescence studies of KBr 1− x I x :TlI (0.01 and 0.05 mol%) mixed crystals grown in vacuum and air are presented. Photoluminescence spectra of the mixed crystals excited in the A-absorption band of KBr:Tl + exhibited the characteristic emission bands of Tl + ions in KBr:Tl +. When excited in the low energy tail of A-band absorption, additional emission bands were observed. Compared with earlier reports, excitation bands observed around 4.8, 4.6 and 4.4 eV are attributed to complex thallium centres of the form TlBr 6− n I n ( n = 0, 1, 2, 3). Photostimulated luminescence of γ-irradiated KBr 1− x I x :TlI mixed crystals showed the presence of emission bands similar to the characteristic photoluminescence of Tl + ions. The photostimulated luminescence slightly shifted towards the low energy side with increasing iodide composition x. The mechanism of emission in these mixed crystals is discussed. Dose response and storage stability (fading characteristics) in these mixed crystals are reported.

Monovalent K, Cs, Tl, and Ag Nitrosodicyanomethanides: Completely Different 3D Networks with Useful Properties of Luminescent Materials and Nonelectric Sensors for Gases

Four K, Cs, Ag(I), and Tl(I) compounds with a nitrosodicyanomethanide ONC(CN)(2)(-) anion have been obtained and characterized using IR spectroscopy; UV-visible spectroscopy; room temperature, solid-state photoluminescence; and solutions electrical conductivity measurements. Cesium and thallium(I) complexes were obtained for the first time, and crystal structures were determined for Cs{ONC(CN)(2)}, Ag{ONC(CN)(2)}, and Tl{ONC(CN)(2)}. These structures indicate the formation of completely different 3D polymeric networks in which the anion acts as a bridging ligand of different capacity. The cyanoxime ligand in all complexes studied is in the nitroso form and adopts a planar configuration. The structure of the cesium salt is ionic. The structure of Ag{ONC(CN)(2)} represents a 3D coordination polymer where the anion acts as a tetradentate ligand with all four bonds between Ag(I) and donor atoms (three N and one O) significantly shorter than the sum of the ionic radii for these elements. The silver(I) atom in this compound has a distorted tetrahedral surrounding. Additionally, Ag{ONC(CN)(2)} is remarkably UV- and visible-light-insensitive. However, after exposure of the solid complex to gases such as H(2), CO, NO, C(2)H(2), and C(2)H(4), the surface of the compound becomes visible-light-sensitive and changes color with significant darkening, which indicates reduction of the metal. This is reflected in a dramatic decrease of intensity of the photoluminescence of Ag[ONC(CN)(2)] in the presence of these gases, which might be utilized for nonelectric sensor applications. The Tl[ONC(CN)(2)] complex represents a transitional species between ionic (Cs) and covalent (Ag) compounds. The thallium(I) center has four shorter bonds than the sum of the ionic radii bonds (three with N and one with O atoms) and three longer electrostatic (ionic) contacts with the anion. The 6s(2) lone pair is stereoactive, and the coordination polyhedron is best described as a distorted square pyramid. Room temperature diffusion reflectance spectra of solid K{ONC(CN)(2)}, Ag{ONC(CN)(2)}, and Tl{ONC(CN)(2)} demonstrated a bathochromic shift of the band's lambda(max) depending on the atomic number of the metal center, indicating a significant role of metal centers in electronic transitions in these compounds. This phenomenon was observed for the first time. The latter complex at 293 K exhibited structured metal-based red photoluminescence in the range of 690-800 nm that depends on the excitation wavelengths.

Luminescent One- And Two-Dimensional Extended Structures and a Loosely Associated Dimer Based on Platinum(II)–Thallium(I) Backbones

Neutralization reactions between (NBu4)2[ trans-Pt(C 6F5)2(CN)2] 1 and (NBu4)2[cis-Pt(C6F5)2(CN)2] 2 with TlPF 6 have been carried out, and the resulting structures of [trans,trans,trans-Tl2{Pt(C6F5)2(CN)2}.(CH3COCH3) ] n [4.(CH3COCH3)2] n and {Tl[Tl{cis-Pt(C6F5)2(CN)2}].(H2O)} n [5.(H2O)] n have been determined by X-ray crystallography. Remarkably, the change from trans to cis geometry on the platinum substrate causes a significant decrease in the Pt(II)...Tl(I) metallophilic interaction. Thus, the platinum center in the trans fragment easily connects with two Tl(I) ions forming a distorted pseudo-octahedron PtTl2, which generates a final two-dimensional layered structure by secondary additional intermolecular Tl(I)...N(CN) interactions. However, the [cis-Pt(C6F5)2(CN)2] (2-) fragment interacts strongly with just one Tl center leading to an extended helical [-Pt-Tl-Pt-Tl-] n(n-) chain. In this case, the second thallium center neutralizes the anionic chain mainly through Tl...N(CN) ( intra) and Tl...F(C 6F 5) (intra and inter)actions. The reaction of TlPF 6 with the monoanionic fragment (NBu4)[cis-Pt(C6F5)2(CN)(PPh2C[triple bond]CPh)] 3 yields the discrete associated dimer [Tl{cis-Pt(C6F5)2(CN)(PPh2C[triple bond]CPh)}] 2 [ 6] 2. Dimer [ 6] 2 could be described as two square pyramids with the thallium atoms in the apical positions, connected through Tl...N(cyano) interactions. The final heteropolynuclear Pt-Tl complexes, except 4 at room temperature, show bright emission in the solid state when irradiated with UV-vis radiation, in contrast to the precursors 1 and 3, which are not luminescent. This difference indicates that the emissions in 4- 6 are presumably related to the interaction between the metal centers. The Pt-Tl bonding interactions and, consequently, the emissive properties are lost in solution at room temperature, as shown by the conductivity and NMR measurements. However, variable-concentration luminescence measurements in glassy acetonitrile solutions indicate the formation of different aggregates with different degrees of Pt...Tl interactions for 4 and 5 and a dimeric structure similar to that observed in solid state for 6.

A Linear Ru‐Tl‐Ru Complex Obtained from Halide Abstraction: An Example of Metal‐Dative Bonding

AbstractThe simple abstraction of chloride ion from [RuCl(CO)2(η‐C5H5)] using [TlBF4] proved problematic, unexpectedly giving a new complex containing linear Ru–Tl–Ru. The complex, [{Ru(CO)2(η‐C5H5)}2(μ‐Tl)(F–BF2–F)]∞, was polymeric, as determined by a single‐crystal X‐ray diffraction experiment, in which the thallium centres are bridged by the anions. In an effort to compare the nature of the Tl–Ru bonds, an additional complex was prepared by the reaction of Tl3+ ions with [Ru(CO)2(η‐C5H5)]–. The resulting neutral complex, [{Ru(CO)2(η‐C5H5)}3(μ‐Tl)], was also structurally characterised. Quantum chemical calculations of [{Ru(CO)2(η‐C5H5)}2(μ‐Tl)][BF4] suggest that the Tl–Ru bond has ionic character with integrated atomic charges showing that the metal–metal bonding is best represented as Ru0–TlI–Ru0. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Easy Ketimine Formation Assisted by Heteropolynuclear Gold−Thallium Complexes

Treatment of the heterometallic complexes [AuTl(C6X5)2(L1)] (X = Cl (1a), F (1b), L1 = ethylenediamine) with ketones at room temperature yields stable amine−imine or diimine complexes with the new ligands bound to the thallium centers. Besides their reactivity in solution, both amine complexes 1a and 1b react in the solid state with ketone vapors at room temperature in a few seconds.

Thallophilic Interactions in Aryloxide Compounds: the {Tl2(μ2-OAr)4} Structural Motif in (TlOAr)4 and Tl2Cu(OAr)4 Compounds

Two thallium aryloxide compounds TlOC6F5 (TlOAr(F)) and bis-3,5-TlOC6H3(CF3)2 (TlOAr') have been recrystallized from THF and crystallographically characterized in different isomeric forms. The latter compound forms a solvated tetrameric cubane, [TlOAr']4.THF, 1. The TlOAr(F) compound crystallized with a similar stoichiometry, [TlOAr(F)]4.2 THF, 2, but contains a [Tl2(mu2-OAr(F))4] unit that includes a thallophilic interaction at a distance of 3.5943(15) angstroms. Solution 205Tl and 203Tl NMR studies of 1 and 2 support the retention of a cubane structure for 1 in solution and suggest a similar structure for 2 with coupled thallium centers down to -90 degrees C. Fluorescence spectroscopy data for both compounds 1 and 2 in THF are consistent with LMCT. DFT calculations of 1, 2, and three models of the [Tl2(mu2-OAr(F))4] unit show a bonding overlap of the bridged thallium atoms in 2 and are also used to describe the bonding in 1. The structures of two heterobimetallic compounds, Tl2Cu(OAr(F))4, 4, and Tl2Cu(OAr')4, 5, with the [Tl2(mu2-OAr(F))4] structural motif and thallophilic contacts of 3.86(6) and 3.564(1) angstroms, respectively, are described. The crystal structures of the unsolvated of TlOAr(F), 2b, solvated heterobimetallic derivative Tl2Cu(OAr')4.2THF, 5b, and the monomeric (18-crown-6)TlOAr(F), 3, and 205Tl NMR spectra of TlOC6H5, 6, are also reported for comparison purposes.

Novel Luminescent Mixed‐Metal PtTl‐Alkynyl‐Based Complexes: The Role of the Alkynyl Substituent in Metallophilic and η2(π⋅⋅⋅Tl)‐Bonding Interactions

A novel series of [PtTl(2)(C[triple chemical bond]CR)(4)](n) (n = 2, R = 4-CH(3)C(6)H(4) (Tol) 1, 1-naphthyl (Np) 2; n = infinity, R = 4-CF(3)C(6)H(4) (Tol(F)) 3) complexes has been synthesized by neutralization reactions between the previously reported [Pt(C[triple chemical bond]CR)(4)](2-) (R = Tol, Tol(F)) or novel (NBu(4))(2)[Pt(C[triple chemical bond]CNp)(4)] platinum precursors and Tl(I) (TlNO(3) or TlPF(6)). The crystal structures of [Pt(2)Tl(4)(C[triple chemical bond]CTol)(8)]4 acetone, 14 acetone, [Pt(2)Tl(4)(C[triple chemical bond]CNp)(8)]3 acetone1/3 H(2)O, 23 acetone 1/3 H(2)O and [[PtTl(2)(C[triple chemical bond]CTol(F))(4)](acetone)S](infinity) (S = acetone 3 a; dioxane 3 b) have been solved by X-ray diffraction studies. Interestingly, whereas in the tolyl (1) and naphthyl (2) derivatives, the thallium centers exhibit a bonding preference for the electron-rich alkyne entities to yield crystal lattices based on sandwich hexanuclear [Pt(2)Tl(4)(C[triple chemical bond]CR)(8)] clusters (with additional Tlacetone (1) or Tlnaphthyl (2) secondary interactions), in the C(6)H(4)CF(3) (Tol(F)) derivatives 3 a and 3 b the basic Pt(II) center forms two unsupported Pt-Tl bonds. As a consequence 3 a and 3 b form an extended columnar structure based on trimetallic slipped PtTl(2)(C[triple chemical bond]CTol(F))(4) units that are connected through secondary Tl(eta(2)-acetylenic) interactions. The luminescent properties of these complexes, which in solution (blue; CH(2)Cl(2) 1,2; acetone 3) are very different to those in solid state (orange), have been studied. Curiously, solid-state emission from 1 is dependent on the presence of acetone (green) and its crystallinity. On the other hand, while a powder sample of 3 is pale yellow and displays blue (457 nm) and orange (611 nm) emissions, the corresponding pellets (KBr, solid) of 3, or the fine powder obtained by grinding, are orange and only exhibit a very intense orange emission (590 nm).

Dimethylsulfoxide gold–thallium complexes. Effects of the metal–metal interactions in the luminescence

The heteropolynuclear complexes [AuTl(C 6X 5) 2] n (X = F, Cl) react with dimethylsulfoxide (DMSO) in different molar ratios leading to products of stoichiometry [Tl 2{Au(C 6F 5) 2} 2{μ-DMSO} 3] n ( 1), and [Tl 2{Au(C 6Cl 5) 2} 2{μ-DMSO} 2] n ( 2). These complexes have been structurally characterized and can be viewed as extended linear chains built with Tl–Au–Tl units in which the thallium atoms are bridged by the oxygen atoms of DMSO ligands. Additional [Au(C 6X 5) 2] − fragments interact with one or two thallium centres, respectively, giving rise to two different types of metal–metal interactions in each molecule. Both of them show a strong luminescence in solid state and complex 2 also in solution. The thallium–thallium interaction in this complex is considered to be the responsible of its luminescence, which remains in solution.

Au−Tl Linear Chains as Lewis Acids toward [Au(C6X5)2]- Metalloligands: The First Anionic Heteropolymetallic Chains

The heteropolynuclear complexes [AuTlR2]n (R = 3,5-C6Cl2F3, C6Cl5) can react with [AuR2]- metalloligands leading to products of stoichiometry {NBu4[Tl2{Au(C6Cl5)2}{μ-Au(C6Cl5)2}2]}n (2), {NBu4[Tl{Au(3,5-C6Cl2F3)2}2]}n (3), or {NBu4[Tl{Au(C6Cl5)2}{Au(3,5-C6Cl2F3)2}]}n (4), which have incorporated a half (2) or one (3, 4) additional gold center per thallium atom. These complexes are the first anionic heteropolymeric chains built via unsupported metal−metal interactions, which are considered to be responsible for the luminescent behavior. These compounds display a strong visible luminescence at room temperature and at 77 K in the solid state under UV excitation, which is sensitive to the structural arrangement of metals as well as to the perhalophenyl group bonded to gold(I). The crystal structures of three of these complexes have been determined by X-ray diffraction crystallography, showing bridging (2) or terminal (3, 4) [AuR2]- fragments bonded to the thallium centers of the principal Au/Tl chain and an almost planar environment for the thallium atoms.

Luminescent Gold(I)-Thallium(I) Arrays through N-Bidentate Building Blocks

Abstract Heteropolynuclear gold(I)-thallium(I) complexes of the type [TlLn][Au(C6F5)2] (L = py (2), 2,2’- bipy (3), 1,10-phen (4) or 4,4’-bipy and THF (5); n = 1, 2) have been obtained from reactions of the corresponding N-donor ligands with the precursor {Tl[Au(C6F5)2]}n (1). The crystal structures of complexes 3 - 5 have been determined by X-ray diffraction showing one- (3, 4) or three-dimensional (5) arrays. All complexes are photoluminescent in the solid state at RT and at 77 K. The strong visible emissions of complexes 2 - 5 are displayed over a wide range of wavelengths (460 - 620 nm) depending on the environment of the thallium(I) centres and on the nature of the N-donor ligand.

A detailed study of the vapochromic Behavior of [Tl[Au(C6Cl5)2]]n.

The linear-chain polymer [Tl[Au(C(6)Cl(5))(2)]](n), 1, reacts in the solid state and in solution with different volatile organic compounds such as tetrahydrofuran, acetone, tetrahydrothiophene, 2-fluoropyridine, acetonitrile, acetylacetone, and pyridine. Solid-state exposure of 1 to vapors of the above VOCs produces a selective and reversible change in its color that is perceptible to the human eye and even deeper under UV irradiation, allowing 1 to function as a sensor for these VOCs. Heating the samples exposed to the VOCs for a few minutes at 100 degrees C regenerates the original material without degradation, even after several exposure/heating cycles. The reversibility is further confirmed by X-ray powder diffraction measurements of complex 1 before and after exposure to vapors and again after heating the samples. The products obtained by reactions of complex 1 with the above VOCs as ligands in solution contain extended linear chains of alternating gold and thallium centers with two molecules of the organic ligands attached to each thallium atom. The stoichiometry of these materials has been confirmed by single-crystal X-ray diffraction as [Tl(THF)(2)[Au(C(6)Cl(5))(2)]](n), 3, and [Tl(acacH)(2)[Au(C(6)Cl(5))(2)]](n), 5. Comparison of FT-IR, UV-vis, and luminescence spectra at room temperature and at 77 K of the solid samples of complexes 2-9 with the spectra of complex 1 after its exposure to VOCs suggests interaction occurs between the organic VOCs and thallium in each case. Thermogravimetric analyses data indicate that all the thallium centers in these derivatives of complex 1 are neither fully nor equally coordinatively saturated. The materials formed appear to be intermediates between complex 1 with no VOCs attached and complexes 3-9 which contain two organic ligands coordinated to each thallium. A crystal structure analyses of one of these intermediates, [Tl(THF)(0.5)[Au(C(6)Cl(5))(2)]](n), 1.0.5THF, confirms this. Density functional calculations are in accord with the observed experimental results. Analysis reveals a substantial participation of the metal atoms in transitions that give rise to the observed emissions. Crystallographic data are as follows. For 1.0.5THF: triclinic, P1, a = 8.9296(1) A, b = 11.2457(1) A, c = 21.2465(3) A, alpha = 96.7187(7) degrees, beta = 92.5886(6) degrees, gamma = 98.5911(8) degrees, V = 2090.87(4) A(3), and Z = 2. For 3: monoclinic, P2(1)/c, a = 26.4163(6) A, b = 12.1619(2) A, c = 28.0813(6) A, alpha = 90 degrees, beta = 161.9823(6) degrees, gamma = 90 degrees, V = 2790.51(10) A(3), and Z = 4. For 5: monoclinic, P2(1)/c, a = 9.8654(2) A, b = 29.8570(5) A, c = 11.6067(2) A, alpha = 90 degrees, beta = 114.5931(6) degrees, gamma = 90 degrees, V = 3108.64(10) A(3), and Z = 4.

Theoretical and Photoluminescence Studies on the d10–s2 AuI–TlI Interaction in Extended Unsupported Chains

The reactions of solutions of TlPF(6) and OPPh(3) in tetrahydrofuran or acetone with NBu(4)[AuR(2)] (R=C(6)Cl(5), C(6)F(5)) gave the new complexes [Au(C(6)Cl(5))(2)](2)[Tl(OPPh(3))][Tl(OPPh(3))(L)] (L=THF (1), acetone (2)) and the previously reported [Tl(OPPh(3))(2)][Au(C(6)F(5))(2)] (3). The crystal structures of complexes 1 and 2 display extended unsupported chains with short intermolecular interactions between alternating gold(I) and thallium(I) centres. Moreover, the Tl(I) centres show two different types of geometrical environments, such as pseudotetrahedral and distorted trigonal-bipyramidal, due to the presence of solvent molecules that act as ligands in the solid-state structure. Quasirelativistic and nonrelativistic ab initio calculations were performed to study the nature of the intermetallic Au(I)-Tl(I) interactions and are consistent with the presence of a high ionic contribution (80 %) and dispersion-type (van der Waals) interaction with a charge-transfer contribution (20 %) when relativistic effects are taken into account. All complexes are luminescent in the solid state at room temperature and at 77 K. Complexes 1 and 2 show site-selective excitation, probably due to the different environments around the Tl(I) centres. The DFT and time-dependent (TD)-DFT calculations are in agreement with the experimental excitation spectra for all complexes and confirm the site-selective excitation behaviour as a function of the Tl(I) geometrical environment.

{AuTl(C6Cl5)2(toluene)}2(dioxane)]: A striking structure that leads to a blue luminescence

The complex [{AuTl(C6Cl5)2(toluene)}2(dioxane)] displays a structure with the thallium(I) center in an unprecedented trigonal planar environment, showing the shortest Au–Tl interaction ever found, a toluene molecule in a η6-mode and the “disappearance” of the Tl(I) inert pair, usually stereochemically active. These characteristics are responsible for its unusual luminescent behaviour.

Four- five- and six-co-ordinated pentafluorophenylthallium(III) complexes.: Crystal structures of [Tl(C 6F 5) 3(OPPh 3)], [Tl(C 6F 5) 2Cl(OPPh 3)] 2 and [Tl(C 6F 5) 2(OdppmO) 2][Tl(C 6F 5) 2Cl 2

[NBu 4][Ag(C 6F 5) 2] or [Ag(C 6F 5)] act as arylating ligands able to transfer two or one pentafluorophenyl groups to [Tl(C 6F 5) 2Cl] leading to [NBu 4][Tl(C 6F 5) 4] ( 1) and [Tl(C 6F 5) 3(diox)] (diox=1,4 dioxane) ( 2) in an improved synthesis, the latter being a starting material for the synthesis of [Tl(C 6F 5) 3(OPPh 3)] ( 3) and [Tl(C 6F 5) 3(PPh 3)] ( 4). However, [Ag(C 6F 5)L] does not transfer the pentafluorophenyl group when reacted with [Tl(C 6F 5) 2Cl] and the complexes [Tl(C 6F 5) 2Cl(py)] 2 ( 5), [Tl(C 6F 5) 2Cl(OPPh 3)] 2 ( 6) and [Tl(C 6F 5) 2(OdppmO) 2][Tl(C 6F 5) 2Cl 2] ( 7) are obtained as the main products, which can be obtained in a better yield by the addition of the neutral ligands to [Tl(C 6F 5) 2Cl]. The X-ray structure of complexes 3, 6 and 7 show thallium(III) centres in a tetrahedral, trigonal bipyramidal or octahedral arrangements, respectively.